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Monkeys chill out just from seeing their friends being groomed

TravelMuse/Alamy Stock Photo

MONKEYS become more relaxed just watching other monkeys grooming each other, a finding that could explain the popularity of online “head orgasm” videos.

Stuart Semple at the University of Roehampton in London and his student Juliette Berthier studied 20 female Barbary macaques in a semi-free ranging group in a safari-park-like environment in a UK forest.

When a macaque saw another being groomed, it started performing fewer “self-directed” behaviours such as scratching and yawning. These are thought to be signs of anxiety, so it seems the macaques were less anxious.